Possibly a few urban myths here.....
If we do not vector off the SIDs (which would go a long way to preventing bunching)
Actually, vectoring off the SIDs has been the CAUSE of much bunching.
There is a "culture" issue here.
As ATCOs (everywhere) we spend our time trying to shorten routes, climb a/c asap etc. Often we are our own worst enemy in that by shorting routes, and not stopping off climbs, we create many more conflicts than would actually exist if everything WAS left on the SIDs and climbed to vertically separated levels.
I might also take issue with:
a) Heathrow and Gatwick SIDS are not separated via DET/DVR
True. But if you stick to VERTICAL separation they can be. The two tracks do not merge until DVR. Ample time for some parallel headings or even a little dog leg to position one behind the other. Positioning is more important than an early climb.
b) A/C would get much later climbs due to A/C now coming into conflict with others that would never have been a problem before....
So? if capacity is increased, being "held down" for 7 mins or so (28 miles) seems a small price (particularly when the overall journey is one of Several HOURS
The ATCOS job becomes much more difficult because there will be lots of A/C 8 miles East of Biggin needing a climb
There's that culture thing again, "Needing a Climb". Sure, they will need to be climbed, but it's NOT that urgent. Better positioning (and capacity) is what we're after here.
d) all of the above would make things less safe
. Disagree here. Safest form of separation is VERTICAL, it's also the quickest and easiest to apply.
Next time you have the opportunity in the SIM, try it.
Keep the sectors split so you have plenty of RT time Leave the a/c on the SIDs, restrict climb to vertically safe levels, and have a go at positioning the a/c in trail later in the SID. All the target levels to AREA are climbing to, rather than level at, so there's no rush.
It IS a BIG culture change, and many people don't react well to change as we are all too well aware. But try it. I have. It DOES actually work.
Best rgds
BEX